Ten years ago, the United Kingdom voted to leave the European Union in a referendum that continues to forge political identities and shattered a half-century project to draw closer to the continent. Brexit, short for British exit, became reality on June 23, 2016, when 52 percent — or more than 17 million people — voted to leave the EU. Though the margin was narrow, the vote led to the most dramatic shake-up of the U.K. economy and society since World War II. But like any divorce, the paperwork and process took nearly five years to complete.

Brexit supporters argued that the British economy could thrive outside the EU by harnessing a buccaneering spirit that had once made it the world's biggest economy. Opponents warned that leaving would lead to economic disruption and risk the country's standing in the world. A decade on, both sides point to evidence supporting their positions.

What the Right Is Saying

Brexit supporters maintain that leaving the EU cannot be judged in the short term and that economic disruption was always anticipated as part of gaining greater control over policy levers, particularly immigration. The message of "taking back control" resonated with millions of voters who felt frustrated not only with the EU but also with broader consequences of the 2008 global financial crisis.

Defenders of Brexit argue there have been meaningful gains in border control. Net migration to Britain has fallen sharply from more than 900,000 in 2023 to 171,000 last year, though immigration from non-EU countries has risen to compensate for reduced EU movement. Supporters say the U.K.'s ability to set its own trade and regulatory policies without EU oversight represents a long-term strategic advantage that will yield benefits over decades rather than years.

What the Left Is Saying

Progressive critics of Brexit argue that leaving the EU has imposed significant economic costs on Britain without delivering the promised benefits. Jonathan Portes, professor at King's College London, said the data tells a clear story: "Brexit has made the U.K. economy smaller than it otherwise would have been." He noted in an article for The UK in a Changing Europe think tank that "the effect has not been a sudden collapse, but a gradual and cumulative drag on trade, investment and productivity."

Progressive voices point to polls showing a shift in public opinion. According to two Ipsos polls, 52 percent of people in the U.K. would like to rejoin the EU while 33 percent are against it. The same polling found that 48 percent think Brexit is going worse than expected, compared with just 9 percent who say it is going better. Forty-eight percent would back another referendum on EU membership today.

What the Numbers Show

The economic data presents a mixed picture, though several key metrics are quantifiable. According to expert estimates cited by The UK in a Changing Europe, the British economy is between 4 percent and 8 percent smaller than it would have been had the country voted to remain in the EU. That shortfall translates to lower living standards and billions of pounds less revenue for public services.

Merchants report ongoing hurdles trading with European neighbors. While no tariffs are imposed on British goods entering the EU, non-tariff barriers including customs paperwork, border certifications, and visa restrictions add complexity. The trade deals promised by Brexit campaigners have largely not materialized, most notably a much-touted agreement with the United States.

The Brexit campaign's signature pledge — an extra 350 million pounds ($468 million) per week for the National Health Service — was emblazoned on their prominent red campaigning bus. That figure has been widely disputed and never delivered in its stated form.

Small boat crossings of the English Channel, which peaked at 46,000 in 2022 and reached 41,000 last year, have become a focal point of political debate despite representing a fraction of overall migration. These crossings involve people often escaping war zones such as Afghanistan and Sudan.

The Bottom Line

Britain's political landscape has fractured significantly since Brexit, with declining support for the two long-dominant parties. The Conservative Party was ejected in 2024 after 14 years in power. Reform U.K., led by Nigel Farage — who perhaps more than any other politician campaigned for Brexit — has led almost every opinion poll for more than a year.

The Labour government under Prime Minister Keir Starmer has sought a "reset" of ties with the EU centered on making trading easier, though it has ruled out reversing Brexit or rejoining the EU's single market. Starmer is expected to announce further measures at an upcoming summit with EU leaders.

The trajectory suggests continued division. With polling showing a majority favoring rejoin and Reform U.K. gaining ground by appealing to voters who feel Brexit was not delivered properly, the political battle over Britain's relationship with Europe remains far from settled.